Vacuum still having heat exchange coils and particle means therewith

ABSTRACT

A METHOD AND APPARATUS FOR DISTILLING LIQUIDS INCLUDING A CLOSED HOUSING VERTICALLY DIVIDED INTO FEED AND DISTILLATE COMPARTMENTS HAVING RESPECTIVELY INTERCOMMUNICATING EVAPORATION AND CONDENSATION CHAMBERS THEREABOVE. A VACUUM IS INDUCED IN THE CHAMBERS BY INTRODUCING A PRIMING CHARGE TO FILL THE HOUSING AND EXPEL THE FREE GASES FROM A VENT IN THE TOP, FOLLOWED BY CLOSING THE VENT AND DISCHARGING A PORTION OF THE PRIMING CHARGE. DISTILLATION IS ACCOMPLISHED BY HEATING THE LIQUID IN THE FEED COMPARTMENT TO PRODUCE VAPOR IN THE EVAPORATION CHAMBER AND BY COOLING THE VAPOR TRANSMITTED TO THE CONDENSATION CHAMBER TO PRODUCE DISTILLATE WHICH DRIPS INTO THE BOTTOM OF THE DISTILLATE COMPARTMENT. AN IRREVRSIBLE HEAT PUMP MAY BE THE MAIN SOURCE OF BOTH HEAT AND COLD. THE TRANSMISSION OF VAPOR FROM EVAPORATION TO CONDENSATION CHAMBERS MAY BE INCREASED BY USING A DUCTED FAN, WHICH WOULD ALSO SERVE BOTH TO DECREASE THE VAPOR PRESSURE IN THE EVAPORATION CHAMBER AND TO INCREASE THE VAPOR PRESSURE IN THE CONDENSATION CHAMBER. TO PREVENT THE SUDDEN FORMATION OF LARGE AMOUNTS OF VAPOR ON THE HEATING COILS IN THE FEED COMPARTMENT, NONBUOYANT SPHERES MAY BE USED ON TOP OF THE COILS AND BUOYANT SPHERES MAY BE USED BELOW THE COILS.   TO INCREASE THE SURFACE OF THE WATER IN THE EVAPORATION CHAMBER, JETS OPERATING BY THE SUCTION OF THE VACUUM MAY BE USED TO INJECT THE LIQUID INTO THE CHAMBER OR INTO THE FEED COMPARTMENT.

Oct. 17, 1972 J. G. HASSLACHER ,6

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITHFiled Aug. 14, 1970 5 Sheets-Sheet 1 x 2 z u; vo- 2 M c C! II 5- (I) S:5 i 5 w m 8 m 5 2 e 2 VALVE-PUMP SYSTEM l2l us T0 RESIDUE STORAGE AREAFROM unmsmuso uo. SUPPLY ATTOIN BY Oct. 17, 1972 J. G. HASSLACHER 3,

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITH 5Sheets-Sheet 2 Filed Aug. 14, 1970 FIG. 2

ATTORNEY Oct. 7, 1972 J. G. HASSLACHER 3,699,006

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITHFiled Aug. 14, 1970 5 Sheets-Sheet 15 VALVE PUMP SYSTEM FIG. 4

ATTOIN BY Oct 1972 J. G. HASSLACHER 3,699,006

VACUUM STILL HAVING HEAT EXCHANGE COILS AND ARTICLE MEANS THEREWITHFiled Aug. 14, 1970 5 Sheets-Sheet 4 5|? 539 540 A SIQW g I IV I J u 534L JV l l :3

b 52l I Oct. 17,

J. G. SSLACHER 3,699,006 VACUUM LL NG T EXCH E COILS A AR LE ME THERE HFiled Aug. 14, 1970 5 Sheets-Sheet 5 Anon United States Patent 3,699,006VACUUM STILL HAVING HEAT EXCHANGE COILS AND PARTICLE MEANS THEREWITHJames G. Hasslacher, 7010 University Drive, Richmond, Va. 23229 FiledAug. 14, 1970, Ser. No. 63,863 Int. Cl. B01d 3/10 US. Cl. 2034 6 ClaimsABSTRACT OF THE DISCLOSURE A method and apparatus for distilling liquidsincluding a closed housing vertically divided into feed and distillatecompartments having respectively intercommunicating evaporation andcondensation chambers thereabove. A vacuum is induced in the chambers byintroducing a priming charge to fill the housing and expel the freegases from a vent in the top, followed by closing the vent anddischarging a portion of the priming charge. Distillation isaccomplished by heating the liquid in the feed compartment to producevapor in the evaporation chamber and by cooling the vapor transmitted tothe condensation chamber to produce distillate which drips into thebottom of the distillate compartment. An irreversible heat pump may bethe main source of both heat and cold. The transmission of vapor fromevaporation to condensation chambers may be increased by using a ductedfan, which would also serve both to decrease the vapor pressure in theevaporation chamber and to increase the vapor pressure in thecondensation chamber. To prevent the sudden formation of large amountsof vapor on the heating coils in the feed compartment, nonbuoyantspheres may be used on top of the coils and buoyant spheres may be usedbelow the coils. To increase the surface of the water in the evaporationchamber, jets operating by the suction of the vacuum may be used toinject the liquid into the chamber or into the feed compartment.

BACKGROUND OF THE INVENTION This invention relates generally todistillation apparatus and more particularly to an apparatus forpurifying polluted, brackish or salt water.

Mankind has been increasingly polluting fresh water and, therebydisturbing the ecology. An economic means must be found to separatewater from liquid or dissolved pollutants.

Nature has for a long time been polluting fresh water with salt. In aridplaces near oceans or salt seas, such as Southern California or NorthernAfrica, and Islands, such as Bermuda, where excessive population,increasing per capita consumption, and agriculture have strained the useof naturally pure water, and inexpensive source of pure water is alsoneeded.

There have been attempts, in the prior art, to provide stills which areadapted to provide fresh water from brackish or sea water in areas suchas those described above. Examples are taught in the US. patent toWalford 3,248,307, issued Apr. 26, 1966, and the patent to Kimmerle3,232,846, issued Feb. 1, 1966, which teaches the use of solar heat.

SUMMARY OF THE INVENTION This invention provides a distillationapparatus which is ideally suited to purify water in economicallydeveloped 3,699,006 Patented Oct. 17, 1972 "ice areas where pollution isa problem or in arid, economically underprivileged areas by furnishing adevice which has inexpensive construction costs, which is simple inoperation, and which operates with a low power requirement.

This invention also provides water of the greatest purity which can beused in such other devices as steam boilers.

This invention further provides a means of salvaging chemicals which inthe past have been discarded because of too great a dilution but whichafter distillation would be concentrated in the residue.

This invention also provides an apparatus which can be employed toreduce such factors as thermal pollution from nuclear reactors byproviding a still which is adapted to utilize waste heat from reactorsas a source.

This invention further provides a use for natural gas in regions whereit has had to be discarded because the region was remote from the areain which the natural gas could be utilized.

This invention also provides a distillation device which is ideallysuited for operation at low power requirements by furnishing anapparatus which utilizes, to a maximum degree, the ambient resourcessuch as gravity, solar heat, and atmospheric pressure.

This invention further provides an apparatus which has a minimum ofmoving parts whereby it is simple and rugged in construction, relativelymaintenance-free, and, therefore, suited for operation in remote and/ortechnically backward areas.

In a preferred embodiment, the invention provides a distillation devicehaving a housing; a wall vertically dividing the housing into a feedcompartment and a distillation compartment; the feed and distillationcompartments each having an inlet and outlet at its base; the feed anddistillate compartments including respectively evaporation andcondensation chambers in the upper ends thereof; means for establishinga vacuum in the chambers; means for transmitting vapor between thechambers; thermal means supplying heat to the feed compartment and coldto the condensation chamber; means to prevent the sudden formation ofvapor on the heating coils; and means to increase the liquid surface inthe feed compartment.

These and other attendant objects and advantages of the invention willbecome better understood by those skilled in the art by reference to thefollowing detailed description when viewed in light of the accompanyingdrawings wherein each figure number is used as the hundreds digit,wherein like components throughout the figures thereof are indicated bylike numerals of tens and units digits (unless there are two or moreadditional like components, in which case letters are added to thenumerals) wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of adistillation device in accordance with the invention;

FIG. 2 is a fragmentary view similar to FIG. 1 showing the use of aducted fan, a variation in accordance with the invention;

FIG. 3 is a fragmentary view similar to FIG. 1 showing the use ofbuoyant and nonbuoyant spheres, variations in accordance with theinvention;

FIG. 4 is a fragmentary view similar to FIG. 1 showing the use of jets,a variation in accordance with the invention;

FIG. 5 is a fragmentary view similar to FIG. 1 showing a valve-pumpsystem in detail in accordance with the invention;

FIG. 6 is a fragmentary view similar to FIGS. 1 and 4, combined, showinga more sophisticated valve-pump system in detail in accordance with theinvention; and

FIG. 7 is a view of the device of FIG. 1 showing a preferredinstallation of a desalinization device in an arid area near a largebody of salty water and near a supply of natural gas,

And wherein the following index gives the tens and units digits and thenomenclature for all the items used in the figures:

INDEX still 01 housing 02 top wall 03 side wall 04 bottom wall 05 feedcompartment 06 distillate compartment 07 dividing wall 08 evaporationchamber 09 condensation chamber 10 vent 11 vent valve 12 heat pumpheating coil 13 heat pump heat conduits 14 heat pump 15 heat pumpcooling coils 16 heat pump cold conduits 17 feed conduit 18 valve-pumpsystem 19 distillate conduit 20 residue conduit 21 intake conduit 22output conduit 23 tank conduit 24 fan structure 25 augmenting heatingcoil 26 augmenting heat conduits 27 buoyant spheres 28 nonbuoyantspheres 29 jet nozzles 30 float 31 upstanding jet conduits 32 jetconduit 33 base conduit 34 flow conduit 35 pump inlet conduit 36 pump 37pump outlet conduit 38 priming conduit 39 connector conduit 40separation conduit 41 intake valve 42 flow valve 43 residue valve 44priming valve 45 separation valve 46 output valve 47 controlled feedconduit 48 reversible connector conduit 49 reversible conduit 50 firstalternate priming conduit 51 feed operational conduit 52 feed pump inletconduit 53 feed pump 54 feed pump outlet conduit 55 second alternatepriming conduit 56 irreversible connector conduit 57 distillateoperational conduit 58 first preferred priming conduit 59 distillatepump inlet conduit 4 60 distillate pump 61 distillate pump outletconduit 62 storage filling conduit 63 second preferred priming conduit:64 reversible valve 65 first alternate priming valve 66 feedoperational valve 67. second alternate priming valve 68 controlled feedvalve 69 distillate operational valve 70- first preferred priming valve71 storage filling valve 72 second preferred priming valve 73 primingstorage tank 74 supports 75 residue storage area 76 intake storage area77 body of salty water 78 dam 79 dam conduit 80 dam valve DESCRIPTION OFTHE PREFERRED EMBODIMENTS On FIG. 1 a still, generally indicated at 100,comprises a housing 101 which is in the form of a frustoconicalenclosure having top, side, and bottom walls 102, 103, and 104 thereto.For economy and durability the housing may be fabricated, asillustrated, from precast or cast in situ concrete or may be fabricatedfrom steel or any other material as desired. The structure may alsocomprise combinations of materials and/or structural techniques as maybe found appropriate from the location and environment at the site.Although the configuration illustrated is generally preferred forconstruction and maintenance purposes (e.g., lack of corners), thehousing may be cylindrical, square, triangular, or any other shape founddesirable within the limits of practicality. The generally taperingwalls illustrated structurally compensate for the change in localpressure on the walls due to static head as is common in the design ofwater-containing structures. The walls may have parallel surfaces or beotherwise conformed as design requirements dictate.

The housing 101 includes bottom, side, and top wall means and isvertically divided into a feed compartment 105 and a distillatecompartment 106 by a dividing wall or partition means 107 which extendsupwardly within the housing 101 to a point spaced from the top wall 102.The dividing wall 107 could also extend to the top of the housing 101and be provided with openings for the purposes of providingcommunication between the compartments. If a barometric leg is used, theminimum height of the dividing wall 107 or any opening therein isdictated by the liquid to be distilled and is a function of the head orexternal height of liquid to be distilled and the external pressure, andthe density of the liquid. The minimum height above the outside liquidheight, for example, can be ascertained by dividing the external,ambient pressure by the liquid density. In case of water at atmosphericpressure, for example, the minimum height is 33.9 feet above the outsidewater level. If a barometric leg is not used, the dividing wall 107 orany opening therein must be sufficiently high to keep the liquid in thefeed compartment 105 separate from the liquid in the distillatecompartment 106.

The areas above the levels of the liquids in the feed and distillatecompartments 105 and 106 comprise evaporation and condensation chambers108 and 109 respectively. A vent 110, controlled by an on-oif valve 111,is disposed at the uppermost point in the still through the top wall 102to provide venting of the chambers 108 and 109.

The feed compartment is provided with a heat exchange means comprising aheating coil 112 which connects through insulated conduits 113 to theheat output side of a heat pump .114. The coil 112 is preferablydisposed to be totally immersed in the liquid in the feed compartment105 and is preferably coated with a deposit and corrosion resistantmaterial such, for example, as polytetrailuoroethylene or the like.Other portions of the still which may be subject to deposit or attackmay be similarly coated if so desired.

The condensation chamber 109 is provided with a heat exchange meanscomprising a cooling coil 115 which is connected to the cold producingside of the heat pump .114 through insulated conduits 116. Care shouldbe taken that, due to low temperatures, condensate does not solidify oraccumulate on the coil 115, thereby reducing the efiiciency thereof.Such conditions may be avoided, if encountered, by providing temperaturesensing means (not shown) which will signal controls to adjust thepressures of the refrigerant in the heat pump.

Although the reverse cycling thereof is not required for this invention,heat pumps suitable for use with this invention are well known in theart as is evidenced by Encyclopedia of Chemical Technology (1953), Kirk-Othmer, vol. 11, page 642, and the operation thereof is understood tothose skilled in the art. In areas where natural gas is abundant, itshould probably be used as fuel for the heat pump, which would besimilarly constructed to those used in a gas refrigerator.

Means other than the heat pump 114 may be utilized in place of or toaugment heating and/or cooling if so desired. Such means would beparticularly appropriate where waste heat or cold is produced as aby-product of some other operation, and such means would be even moredesirable where use of waste heat from a nuclear reactor, for example,would preclude or reduce thermal pollution of the environment while, atthe same time, reducing or eliminating the heat requirements of thestill. Solar heaters and other similar devices may also be incorporatedto similarly reduce heat input requirements.

The housing 101 is provided with a feed conduit 117 which iscommunicative with both a lower portion of the feed compartment 105 anda valve-pump system 118. The housing is also provided with a distillateconduit 119 which is communicative with both a lower portion of thedistillate compartment 106 and the valve-pump system 118. The valve-pumpsystem 118 is also communicative with and controls the flow in: aresidue conduit 120', which goes to the residue storage area; an intakeconduit 121, which comes from the supply of the liquid to be distilled;an output conduit 122, from which the pure distillate leaves the still100; and a tank conduit 123, which goes to the priming storage tank. Amore detailed description of the valve-pump system 118 appears post.

In operation, the vent valve 111 is opened, and a priming charge isintroduced into the housing 101. Where rapid start-up is desired, thepriming charge comprises distilled liquid, preferably from a previouscycle. When there is no priming storage tank because of the expenseinvolved in its construction or when there has been no previous cycle,the priming charge must comprise undistilled liquid, and the liquid inthe distillate compartment 106 must be routed to the feed compartment105 until the liquid in the distillate compartment 106 is pure. Thisrouting takes place through the distillate conduit 11 9, the valve-pumpsystem 118, and the feed conduit 117.

The housing 101 is filled at least to the top of sloped top wall 102 toeliminate all of the free gases from the interior, whereupon the ventvalve 111 is closed. Then the priming charge is allowed to drain or ispumped out of the housing 101 until the liquid level in the compartments105 and 106 is below the top of the dividing wall 107 or any openingstherein. Next, the heat pump 114 is turned on, and after the distillatehas become pure, the distillate is removed from the still 100. Theoperation of the still is continuous, until, in some cases, the residuehas to be removed.

In the embodiment of FIG. 2, components thereof corresponding to likecomponents in the preceding embodiments are indicated by like numerals,only of the next higher order. In this embodiment, the primarydistinction over the embodiment in FIG. 1 is the fan structure 224. Thefan in this embodiment is ducted because it sits in a round opening inthe dividing wall 207. There may be more than one fan, and the fans maynot be ducted, although ducting greatly increases the efiiciency of thefan operation, as is known in the art. With a ducted structure, however,gas can be trapped on either side of the uppermost part of the dividingwall 207 during the abovedescribed priming operation, and it is,therefore, required that vents 210a and 21% be provided at the uppermostparts of the top wall 202 on opposite sides of the dividing wall 207.The vents 210a and 21% are valved by means of on-otf valves 211a and211b, respectively. The fan or fans are turned on at the same time asthe heat pumps. Other than the above-described changes, the remainder ofthe device of FIG. 2 is identical to and operates in the same manner asthe above-described embodiment.

The fans serve a quintuple purpose, as is known in the art. Theydecrease the pressure in the evaporation chamber and increase thecirculation over the surface of the undistilled liquid, thereby causingincreased evaporation of the undistilled liquid. They increase the flowbetween the evaporation and condensation chambers. They increase thepressure in the condensation chamber and increase the circulation overthe cooling coils, thereby causing increased condensation of thedistillate.

To prevent the sudden formation of large quantities of vapor, commonlycalled thumping or bumping, chem ists use glass beads or bits of brokencrockery in test tubes and flasks, which are heated externally. Asimilar problem arises in an internally heated device. If thumpingoccurs, large quantities of undistilled liquid will mix with pure vaporand pass over to the condensation chamber, thereby polluting thedistillate.

FIG. 3, which is also a fragmentary view similar to FIG. 1, illustratesa solution to this problem. The heat pump heating coil, generallyindicated at 312, which is supplied heat by insulated heat pump heatconduits 313, is disposed in horizontal grids. The augmenting heatingcoil, generally indicated at 325, which is supplied heat by insulatedaugmenting heat conduits 326, is also disposed in horizontal grids.(N.B. only part of the augmenting heating system is shown. Crosses anddots in the heating coils are used to indicate the direction of internalflow.) Buoyant particles or spheres 327a, 327b, and 327a are placedbelow each layer of horizontal grid. Nonbuoyant particles or spheres328a, 328b, 9280, and 328d are placed above each layer of horizontalgrid.

Both types of spheres may be made of the same material if buoyancy iscontrolled by using heavier cores or by using hollow centers. Thespheres will not pass through a horizontal grid if the transversedimension or width of every particle or diameter of every sphere isgreater or larger than the horizontal gap between each part of theheating coils or between the coils and the side wall 303 or between thecoils and the dividing wall 307. Care should be taken that the spheresdo not bend the coils, which may be strengthened by fins or transverserods anchored to the adjacent walls.

The use of buoyant (low density) and non buoyant (high density)particles, spheres, and the like in gasliquid contacting systems isknown in the art, as exemplified in US. Pats. No. 3,122,594 to Kielback;No. 3,302,372 to Hynson et al.; No. 3,348,825 to McIlvaine; and No. 3,-409,279 to Metrailer. Applicant has adapted the theories expressed insuch disclosures in the present vacuum still and the above patents areincorporated by reference in this application.

In FIG. 4, which is also a fragmentary view similar to FIG. 1, jetswhich operate on the principle that a vacuum Will suck in a liquid areillustrated. In a still using the barometric leg, the jet nozzles 429must be below the minimum height of the dividing wall 407 or any openingtherein. In a vacuum still not using a barometric leg, a float 430 maybe used to sense the level of the liquid in the feed compartment 405.The float 430 may not be too close to the nozzles 429, because it mightbe pushed up by the action of the jet and, thereby, lose itselfectiveness. The nozzles 429 must also not be too near a fan, becausethe fan might transport spray with vapor. The lower the nozzles 429 arefrom the surface of the liquid in the compartment 405, the lower will bethe height of the fountain, and, hence, the less will be the increase inthe surface area of the liquid in feed compartment 405. As is known inthe art, more surface area in the feed compartment 405 means that moreevaporation takes place in the evaporation chamber 408 and, thereby,that the efficiency of the still is increased.

The jet nozzles 429 are part of upstanding jet conduits 431, whichbranch from a jet conduit 432. The jet conduit 432 comes from avalve-pump system 418. A base conduit 433 also comes from the valve-pumpsystem 418 and goes to the feed compartment 405. The base conduit 433and the jet conduit 432 together take the place of the feed conduit 117.

There are many types of valve-pump systems which can be used in thestill. FIG. is a fragmentary view of FIG. 1, except that the tankconduit 123 is omitted, and illustrates a valve-pump system 518 which isused in a less expensive variation of the still where the distillate isof primary importance. The intake conduit 521 communicates with a firstT member, which further consists of a flow conduit 534 and a pump inletconduit 535. [Each small circle with a V indicates a valve which will bedescribed below. The pump inlet conduit 535 leads to a unidirectionalpump 536, from which comes a pump outlet conduit 537. The pump outletconduit 537, in turn, communicates with a second T member, which alsoconsists of the residue conduit 520 and a priming conduit 538. Thepriming conduit 538 next leads to a third T member, which further iscomposed of the feed conduit 517 and a connector conduit 539. Theconnector conduit 539 then forms a fourth T member, the other parts ofwhich are the flow conduit 534 and a separation conduit 540. Theseparation conduit 540 also communicates with a last T member, whichalso consists of the distillate conduit 519 and the output conduit 522.This valve-pump system 518 also consists of the following on-ofl?valves: an intake valve 541 on the intake conduit 521, a flow valve 542on the flow conduit 534, a residue valve 543 on the residue conduit 520,a priming valve 544 on the priming conduit 538, a separation valve 545on the separation conduit 540, and an output valve 546 on the outputconduit 522. Pump 536 is controlled by an on-otf switch.

In the below description of the valve-pump system 518 in operation, thepump and all valves are considered to be oif unless they are specifiedas being on. The still operates without jets and on a barometric leg. Toprime the still the pump 536 is turned on, and the vent valve 111(FIG. 1) and valves 541 and 544 are opened. In forming the vacuum onlyvalves 541, 542, and 545 are opened. If recycling is needed to purifythe distillate after priming or at any other time, only valve 545 isopened. Normal operation of the still takes place when only valves 541,542, and 546 are opened. The residue is removed by turning on the pump536 and opening valves 542 and 543, during which time valve 546 may beleft open. The housing may be emptied by opening the vent valve 111,valve 546 and either valves 543 and 544 if the residue is to be saved,or valves 541 and 542 if the residue is not concentrated enough to besaved. The heat pump and/or the fan or fans are turned on only duringrecycling and normal operation.

A more sophisticated valve-pum system 618, used where the residue is ofprimary importance, is shown in FIG. 6, which has the embodiments ofFIG. 1 as modified by the embodiments of FIG. 4. The still, in thiscase, does not operate by using a barometric leg, nor would its primingstorage tank return flow be operated mainly by the force of gravity.This variation of the still has jets and probably fan or fans. Valvesare controlled by electric power. There must be a device, such as afloat so rigged as to put out electrical signals, in the priming storagetank and in both the feed and the distillate compartments to determinethe height of the liquid in each. Both feed and distillate compartmentshave individual monitors capable of putting out electric signals todetermine the purity of the liquid. Such devices, as is known by thoseskilled in the art, usually work on electrical conductivity.Electrically signaling monitors capable of distinguishing between airand liquid are required on the base conduit 633, on the distillateconduit 619, and on the vent above the vent valve 111. Twounidirectional pumps 653 and 660 are also used. The still operates bothcontinuously and automatically.

An intake conduit 621 communicates with a first T member, which alsoconsists of a controlled feed conduit 647 and a reversible connectorconduit 648. The reversible connector conduit 648 goes to a second Tmember, from which also comes a reversible conduit 649 and a firstalternate priming conduit 650. The first alternate priming conduit 650leads to a third T member, which further consists of a feed operationalconduit 651 and a feed pump inlet conduit 652. After a feed pump 653,comes a feed pump outlet conduit 654. The feed pump outlet conduit 654communicates with a first cross member, which also communicates with thereversible conduit 649, a residue conduit 620, and a second alternatepriming conduit 655. The second alternate priming conduit 655 then goesto a fourth T member, which also connects with a base conduit 633 andwith the feed operational conduit 651.

The controlled feed conduit 647 leads to a fifth T memher, to which alsocomes a jet conduit 632 and a separation conduit 640. The separationconduit 640 communicates with a sixth T member, which furthercommunicates with an irreversible connector conduit 656 and a distillateoperational conduit 657. The distillate operational conduit 657 goes toa seventh T member, from which comes a first preferred priming conduit658 and a distillate pump inlet conduit 659. The distillate pump 660communicates with a distillate pump outlet conduit 661. The distillatepump outlet conduit 661 leads to a second member, which also connectswith an output conduit 622, a storage filling conduit 662, and a secondpreferred priming conduit 663. The storoge filling conduit 662 goes intoan eighth T member, from which comes the first preferred priming conduit658 and a tank conduit 623, and the second preferred priming conduit 663goes into a ninth T member, from which comes the irreversible connectorconduit 656 and a distillate conduit 619.

The valve-pump system 618 also consists of the following electricallycontrolled on-off valves, each of which is designated by a small circlewith a V: a reversible valve 664 on the reversible conduit 649, a firstalternate priming valve 665 on the first alternate priming conduit 650,a feed operational valve 666 on the feed operational conduit 651, aresidue valve 643 on the residue conduit 620, a second alternate primingvalve 667 on the second alternate priming conduit 655, a controlled feedvalve 668 on the controlled feed conduit 647, a separation valve 645 onthe separation conduit 640, a distillate operational valve 669 on thedistillate operational conduit 657, a first preferred priming valve 670on the firs-t preferred priming conduit 658, an output valve 646 on theoutput conduit 622, a storage filling valve 671 on the storage fillingconduit 662, and a second preferred priming valve 672 on the secondpreferred priming conduit 663.

Before operation, all pumps, heat pumps, fans, and valves are off orclosed. To begin operation the automatic control switch is turned on. Ifthere is sufiicient liquid to fill the housing as determined by thefioat inside the priming storage tank, pump 660 is turned on and ventvalve 111 and valves 670 and 672 are opened. If there is insufiicientliquid, pump 653 is turned on and vent valve 111 and valves 665 and 667are opened. After the housing has been primed as determined by liquidbeing above the vent valve 111, all valves including the vent valve 111are closed, and if it is on, pump 660 is turned off. A vacuum is formedby opening valves 664, 666 and 645, and if it is not already on, byturning on pump 653. The termination of vacuum formation occurs when the{float in the distillate compartment indicates that the level of theliquid is lower than the top of or the holes in the dividing wall. Afterthe vacuum has been formed, recycling begins and all valves except valve645 are closed. The pump 653 is turned off, and the heat pump and fan orfans, if they are used, are turned on. Recycling continues until themonitor determining the purity of the liquid in the distillatecompartment indicates the liquid is pure. It is then stopped by closingvalve 645. Recycling begins again anytime the distillate becomes impureas determined by the monitor in the distillate compartment. New,unprocessed liquid enters the still by opening valve 668 whenever theliquid level in the feed compartment becomes too low, as indicated bythe float in the feed compartment. The float in the distillatecompartment determines when the distillate should be removed. When itshould be removed, valve 669 is opened, pump 660 is turned on, andeither valve 671 is opened if the priming storage tank needs filling asdetermined by the float in the tank or valve 646 is opened. The monitorwhich measures the impurity of the residue in the feed compartmentdetermines when the residue should be removed. When it should beremoved, valves 666 and 643 are opened and pump 653 is turned on.

To cease operation the automatic control switch is turned off. The heatpump and the fan or fans, if they areused, are turned off by theautomatic control switch, which also turns on pump 653 and 660 and opensthe vent valve 111 and valves 666, 669 and 646. If the residue isconcentrated enough to send to the residue storage area as determined bythe purity monitor in the feed compartment, valve 643 is opened. If theresidue is not concentrated enough, valve 664 is opened. All othervalves are closed. Pump 653 runs until air begins coming into the baseconduit 633, and pump 660 runs until air begins coming into thedistillate conduit 619. When both pumps 653 and 660 stop, all valvesincluding the vent valve 111 are closed, and the still is ready to beginoperation again.

FIG. 7 shows a preferred installation of the still 700 already shown inFIG. 1. It is the type built in an arid area, preferably near a largesupply of natural gas, since the heat pump 714 can use natural gas asfuel and the electricity for the pump or pumps can be generated by alsousing natural gas as fuel. The still would not only make pure water butwould allow salt to be recovered as a by-product. The housing 701 wouldbe so constructed that the feed chamber would face into the sun and thedistillate chamber would face away from the sun (i.e., in the northernhemisphere the feed chamber would be southward, and in the southernhemisphere the feed chamher would be northward). The housing 701 wouldalso be built on a hill so that it would not have to be so high and itswalls would not have to be so thick. Internal rinsing of the housing 701would also be lessened since the volume of the distillate compartmentwould be made smaller. Incidentally, evaporation in the distillatecompartment would be even less if surface area of the distillate werereduced. A priming storage tank 773 is located above the housing 701 onsupports 774 so that the preferable priming can be done by gravity. Aresidue storage area 775 would be shallow, would be open and would haveits bottom coated black in order to increase final evaporation. Inwetter areas, of course, the residue area would be covered, and theshape of the tank would be engineered so as to hold the residue better.An intake storage area 776 would also have its bottom coated black forpreheating purposes, but it would be deeper to slow evaporation. Theintake storage area 776 would be separated from a nearby body of saltywater 777 by a dam 778 having a dam conduit 779 with a dam valve 780.The whole dam structure prevents fluctuation of the barometric legcaused by tides and waves if the dam valve 780 is opened only at hightides. Operation of the still 700 would occur as described above.

I claim:

1. A liquid distillation device comprising wall means including bottom,side, and top wall means defining a housing, vertically extendingpartition means projecting upwardly from said bottom and dividing theinterior of said housing into side by side feed and distillatecompartments, conduit means communicating with the lower portion of eachof said compartments, vent means at the top of said housing, valve meansfor controlling said vent means, said partition means having at leastone opening therein beneath the top wall means of said housing toprovide vapor intercommunication between said compartments, means forcontrolling liquid flow through both said conduit means, means forestablishing a vacuum in the upper portion of said compartments so as toconstitute the same as evaporation and condensation chambers comprisingpriming means communicating with one of said conduit means forintroducing a priming charge of liquid into the lower portion of atleast one of said compartments with said valve means for said vent meansopen to completely fill said compartments to exclude noncondensablegases from within said housing, the closing of said valve means and thedischarge of a portion of said liquid from the other of saidcompartments establishing a vacuum in said chambers above the level ofthe lower part of said opening in said partition means, a heat exchangerwithin said feed compartment below the level of said opening in saidpartition means and thus below the liquid level therein for applyingheat to such liquid to produce vapor in the evaporation chamber to flowthrough said opening in said partition means into said condensationchamber, cold producing coil means arranged in said condensation chamberabove the level of said opening in said partition means for cooling thevapor transmitted to the condensation chamber to establish a distillatein said distillate compartment, said heat exchanger including heattransfer medium receiving conduit means arranged in at least onehorizontally extending layer, buoyant particles disposed beneath theconduit means of said layer to curtail sudden formation of vapor duringdistillation, and said particles having a transverse dimension greaterthan any horizontal gap between the conduit means in such layer andbetween the end conduit means of such layer and the adjacent side wallmeans and partition means.

2. A liquid distillation device comprising wall means including bottom,side, and top wall means defining a housing, vertically extendingpartition means projecting upwardly from said bottom and dividing theinterior of said housing into side by side feed and distillatecompartments, conduit means communicating with the lower portion of eachof said compartments, vent means at the top of said housing, valve meansfor controlling said vent means, said partition means having at leastone opening therein beneath the top wall means of said housing toprovide vapor intercommunication between said compartments, means forcontrolling liquid flow through both said conduit means, means forestablishing a vacuum in the upper portion of said compartments so as toconstitute the same as evaporation and condensation chambers comprisingpriming means communicating with one of said conduit means forintroducing a priming charge of liquid into the lower portion of atleast one of said compartments with said valve means for said vent meansopen to completely fill said compartments to exclude non-condensablegases from within said housing, the closing of said valve means and thedischarge of a portion of said liquid from the other of saidcompartments establishing a vacuum in said chambers above the level ofthe lower part of said opening in said partition means, a heat exchangerwithin said feed compartment below the level of said opening in saidpartition means and thus below the liquid level therein for applyingheat to such liquid to produce vapor in the evaporation chamber to flowthrough said opening in said partition means into said condensationchamber, cold producing coil means arranged in said condensation chamberabove the level of said opening in said partition means for cooling thevapor transmitted to the condensation chamber to establish a distillatein said distillate compartment, said heat exchanger including heattransfer medium receiving conduit means arranged in at least onehorizontally extending layer, nonbuoyant particles disposed on top ofthe conduit means of said layer to curtail sudden formation of vaporduring distillation, and said particles having a transverse dimensiongreater than any horizontal gap between the conduit means in such layerand between the end conduit means of such layer and the adjacent sidewall means and partition means.

3. A liquid distillation device comprising wall means including bottom,side, and top wall means defining a housing, vertically extendingpartition means projecting upwardly from said bottom and dividing theinterior of said housing into side by side feed and distillatecompartments, conduit means communicating with the lower portion of eachof said compartments, vent means at the top of said housing, valve meansfor controlling said vent means, said partition means having at leastone opening therein beneath the top wall means of said housing toprovide vapor intercommunication between said compartments, means forcontrolling liquid flow through both said conduit means, means forestablishing a vacuum in the upper portion of said compartments so as toconstitute the same as evaporation and condensation chambers comprisingpriming means communicating with one of said conduit means forintroducing a priming charge of liquid into the lower portion of atleast one of said compartments with said valve means for said vent meansopen to completely fill said compartments to exclude non-condensablegases from within said housing, the closing of said valve means and thedischarge of a portion of said liquid from the other of saidcompartments establishing a vacuum in said chambers above the level ofthe lower part of said opening in said partition means, a heat exchangerwithin said feed compartment below the level of said opening in saidpartition means and thus below the liquid level therein for applyingheat to such liquid to produce vapor in the evaporation chamber to flowthrough said opening in said partition means into said condensationchamber, cold producing coil means arranged in said condensation chamberabove the level of said opening in said partition means for cooling thevapor transmitted to the condensation chamber to establish a distillatein said distillate compartment, said heat exchanger including heattransfer medium receiving conduit means arranged in at least onehorizontally extending layer, buoyant and non-buoyant particles disposedrespectively beneath and on top of the conduit means of said layer tocurtail sudden formation of vapor during distillation, and saidparticles having transverse dimen sion greater than any horizontal gapbetween the conduit means in such layer and between the end conduitmeans of such layer and the adjacent side wall means and partitionmeans.

4. A method of distilling liquid comprising providing an enclosurearound side by side feed and distillate compartments, providing intercommunication between the upper portions of said compartments, opening avent at the top of at least one of said compartments, introducing apriming charge of liquid into the lower portion of at least one of saidcompartments sufficient to fill both compartments with liquid so as toexclude all noncondensable gases therefrom, closing said vent,discharging a portion of said introduced liquid from the lower portionof at least one of said compartments to induce a vacuum in the upperportion of both of said compartments, applying heat directly to theliquid in one compartment through at least one layer of a heatexchanging coil disposed beneath the level of the liquid in said onecompartment to evaporate liquid therein to produce vapor in the upperportion thereof to flow into the upper portion of the other compartment,preventing too rapid a formation of vapor by providing buoyant particlesbeneath the coil of the layer with such particles having a transversedimension greater than any gap formed between and relative to the coilof such layer, condensing said vapor in said other compartment bycontacting the same with at least one cold producing coil in the upperportion of said other compartment to form a distillate and withdrawingsuch distillate from the lower portion of said other compartment.

5. A method of distilling liquid comprising providing an enclosurearound side by side feed and distillate compartments, providingintercommunication between the upper portions of said compartments,opening a vent at the top of at least one of said compartments,introducing a priming charge of liquid into the lower portion of atleast one of said compartments sufiicient to till both compartments withliquid so as to exclude all noncondensable gases therefrom, closing saidvent, discharging a portion of said introduced liquid from the lowerportion of at least one of said compartments to induce a vacuum in theupper portion of both of said compartments, applying heat directly tothe liquid in one compartment through at least one layer of a heatexchanging coil disposed beneath the level of the liquid in said onecompartment to evaporate liquid therein to produce vapor in the upperportion thereof to flow into the upper portion of the other compartment,preventing too rapid a formation of vapor by providing non-buoyantparticles on top of the coil of the layer with such particles having atransverse dimension greater than any gap formed between and relative tothe coil of such layer, condensing said vapor in said other compartmentby contacting the same with at least one cold producing coil in theupper portion of said other compartment to form a distillate andwithdrawing such distillate from the lower portion of said othercompartment.

6. A method of distilling liquid comprising providing an enclosurearound side by side feed and distillate compartments, providingintercommunication between the upper portions of said compartments,opening a vent at the top of at least one of said compartments,introducing a priming charge of liquid into the lower portion of atleast one of said compartments suflicient to fill both compartments withliquid so as to exclude all noncondensable gases therefrom, closing saidvent, discharging a portion of said introduced liquid from the lowerportion of at least one of said compartments to induce a vacuum in theupper portion of both of said compartments, applying heat directly tothe liquid in one compartment through at least one layer of a heatexchanging coil disposed beneath the level of the liquid in said onecompartment to evaporate liquid therein to produce vapor in the upperportion thereof to flow into the upper portion of the other compartment,preventing too rapid a formation of vapor by providing buoyant andnon-buoyant particles respectively beneath and on top of the coil of thelayer with such particles having a transverse dimension greater than anygap formed between and relative to the coil of such layer, condensingsaid vapor in said other compartment by contacting the same with atleast one cold producing coil in the upper portion of said othercompartment to form a distillate and withdrawing such distillate fromthe lower portion of said other compartment.

References Cited UNITED STATES PATENTS Stone 203-26 Ross 203-DIG 17Lusknader 203-11 Cummings 20'3-11 Harper 203-11 Adrassy 159-1 S Day203-26 14 Grow 203-11 Creskoif 203-11 Hardy 159-1 S Bie 203-11 Brown202-205 Schenk 202-205 Bimpson et a1. 202-205 WILBUR L. BASCOMB, JR.,Primary Examiner US. Cl. X.R.

159-1 S; 202-205, 234, 236; 203-11, 26, 90, 91, DIG 1, DIG 4, DIG 7, DIG17; 261-94 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. B699QOO6 Dated fI 17, 197

Inve James G. Hasslacher It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column l line 50, "Islands" should read islands Column 6', line 32,"chem" should read chem- Column 6 1ine 51, "928 should read 52a Column8, line #7, between "second" and "member" cross should be inserted.

Column 8, line 50, "storoge" should read storage Column 13, line '9,"Lusknader" should read Lustenader Column 13, line 12, "Adrassy" shouldread Andrassy IN THE DRAWING: I

The drawing should be corrected as follows:

-- In Fig. 7, the heat pump cold conduits connected to the top of heatpump 71 and now bearing the numeral "71 should read 716 Signed andsealed this 20th day of August 197 ERE S i McCOY GIBSON, JR. C. MARSHALLDANN 1 I Attesting Officer Commissioner of Patents FORM P0-1 0 YuscoMM-Dc 6O376-P69 fi' U.S, GOVERNMENT PRINTING OFFICE I 9'9 0-366-33I.

